Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities
Net income (loss)	$ (78,733)	$ (407,088)	$ (51,396)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	34,399	49,998	50,095
Non-cash interest expense	12,676	11,762	10,446
Deferred income taxes	360	(27,620)	(35,363)
Share-based compensation expense	15,270	16,074	24,396
Asset impairment	4,020	375,172	1,139
Impairment of equity investments	20,973	0	0
Provision for bad debts	392		99
Changes in operating assets and liabilities:
Accounts receivable and contract assets	5,796	21,821	10,240
Inventories and deferred cost of sales	14,969	(24,678)	6,244
Prepaid expenses and other current assets	7,520	11,216	(10,204)
Accounts payable and accrued expenses	(26,945)	(19,672)	11,308
Customer deposits and deferred revenue	(17,866)	(39,296)	22,446
Income taxes receivable and payable, net	(655)	(4,800)	775
Long-term income tax liability			(4,877)
Other, net	408	(627)	(355)
Net cash provided by (used in) operating activities	(7,416)	(37,738)	34,993
Cash Flows from Investing Activities
Acquisitions of businesses, net of cash acquired		(2,662)	(401,828)
Capital expenditures	(10,873)	(12,654)	(24,272)
Proceeds from the sale of investments	127,349	90,065	348,927
Payments for purchases of investments	(192,988)	(93,046)	(282,947)
Proceeds from held for sale assets	645		2,284
Net cash provided by (used in) investing activities	(75,867)	(18,297)	(357,836)
Cash Flows from Financing Activities
Proceeds (net of tax withholdings) from option exercises and employee stock purchase plan	3,106	3,064	2,992
Restricted stock tax withholdings	(2,980)	(3,069)	(8,741)
Purchases of common stock		(11,457)	(2,869)
Proceeds from long-term debt borrowings			335,752
Principal payments on long-term debt			(1,194)
Net cash provided by (used in) financing activities	126	(11,462)	325,940
Effect of exchange rate changes on cash and cash equivalents	26	(4)	42
Net increase (decrease) in cash, cash equivalents, and restricted cash	(83,131)	(67,501)	3,139
Cash, cash equivalents, and restricted cash - beginning of period	213,082	280,583	277,444
Cash, cash equivalents, and restricted cash - end of period	129,951	213,082	280,583
Supplemental Disclosure of Cash Flow Information
Interest paid	9,408	9,708	4,675
Income taxes paid	2,931	4,799	1,939
Non-cash operating and financing activities
Net transfer of inventory to property, plant and equipment	4,916	$ 1,479	$ (97)
Right-of-use assets obtained in exchange for lease obligations	$ 5,576